Electron devices employing free space transport of electrons are known in the art. Generally, such devices employ an electron source which emits electrons which have acquired sufficient energy to overcome a surface barrier potential. In one commonly employed prior art method of providing emitted electrons, thermal energy is added to elevate electrons, disposed in the electron source, to a higher energy state which exceeds the potential barrier. In another commonly employed method of the prior art, structures comprised of geometric discontinuities of very small radius of curvature, on the order of 500 Angstroms, are employed.
In the instance of the devices employing electron sources wherein the additional energy is introduced as thermal energy, overall device efficiency is reduced as is the opportunity for integration of the structure. In the instance of devices employing electron sources exhibiting features with geometric discontinuities of small radius of curvature the need to employ complex fabrication processes poses some limitation on the practicality and utility of the electron source.
Accordingly there exists a need for an electron device employing an electron source which overcomes at least some of the shortcomings of the prior art.